Small intestinal presentation of nodular lymphocyte-predominant Hodgkin lymphoma with T cell/histiocyte-rich B cell lymphoma-like areas-with review of literature on extranodal presentation of this disease.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), accounts for ∼5% of all cases of Hodgkin lymphoma and is characterized by involvement of the peripheral lymph nodes. NLPHL occurs in young adults and is associated with frequent relapses. In 3% to 7% of cases, NLPHL progresses to a diffuse large B cell lymphoma. Furthermore, a proportion of NLPHL also have areas with features of T cell/histiocyte-rich large B cell lymphoma (THRLBCL), either at presentation or on follow-up. Here, we describe a 32-year-old man who presented to the emergency department with small bowel perforation. The resected small bowel showed full-thickness mural ulceration and involvement by a lymphoma with features of NLPHL that also had areas resembling THRLBCL. The patient had axillary lymphadenopathy, biopsy of which showed NLPHL with focal THRLBCL-like areas. Such a lymphoma presenting as small intestinal lesion/perforation has not been reported in the literature before. We take this opportunity to review the literature on extranodal presentations of NLPHL and discuss the natural history of this disease.

Cyclin D1 expression in typical chronic lymphocytic leukaemia.

Demonstration of cyclin D1 expression by immunohistochemistry in a CD5-positive small B-cell proliferation is extremely helpful in the diagnosis of mantle cell lymphoma in tissue samples, including bone marrow trephine biopsies (BMTB) and in differentiating them from chronic lymphocytic leukaemia (CLL). Following the identification of cyclin D1 expression in one case of CLL on BMTB, 64 additional cases, which included 25 lymph nodes, one tonsillar lesion, one skin lesion and 37 BMTBs were systematically reviewed for presence of cyclin D1 overexpression. Overall, in seven of 65 samples (approximately 10%) of CLL, a minority of the leukaemic cells in the proliferation centres expressed cyclin D1. Cytogenetic analysis had been performed in three of seven cases and there was no evidence of translocation involving CCND1 locus. Our findings suggest that a small subset of CLL overexpresses cyclin D1 in amounts that can be demonstrated by immunohistochemistry. Our observation has impact on the diagnosis of small B-cell lymphomas in BMTB and other tissue samples.